Strut for automatic sprinklers



W. GRIMSHAW VSTRUT FOR AUTOMIATIC SPRINKLERS Aug. .7, 1928. 1,679,568

Filed Aug. 25, 1923 Patented Aug. 7, 1928.

UNITED STATES WILLIAM GRIMSHAW, 0F GLEN ELLYN, ILLINOIS.

STRUT FOR AUTOMATIC SPRINKLERS.

Application led August 25,V 1923. Serial No. 659,294.

This invention relates to struts for automatic sprinklers used forsecuring the caps or valves of the sprinklers in closed position, andrelates particularly to struts of the toggle type.

The invention also relates to an improved process of producing struts ofthe type speci- Vfied.

As the invention relates to the article, the object of the invention isto )rovide an improved strut of the type speci ed, which will berelatively many times stronger than struts now commonly used, all ofwhich will be facsimiles of one another, both as regards shape, size andresistance to withstand stresses, and which may be produced inquantities at lrelatively very small cost.

As the invention relates to a process of manufacture, the object of theinvention is to provide a practical process for producing strutspossessing the foregoing characteristics, whereby said struts ofrelative great strength may be produced in quantities atV relativelyvery small cost as compared with present methods of manufacture.

' To effect the objects of the inventionmy improved process consists inpunching blanks from suitable sheet metal, and in shaping said blankstothe form ofthe finished article by successive swaging operations inprogressively conforming dies and as the invention relates to an articleofmanufacture, I attain the object of the invention by subjecting asuitable blank to the various steps or operations which constitute my1mproved process.

In the accompanying drawing, in which the steps or operations comprisingmy improved process and the finished strut members resulting therefromare illustrated,

Figure l is a diagrammatic view showing a strut of the general type towhich my invention relates, as applied in use for securing the cap orvalve of the sprinkler in closed position.

Figure 2 is a side view of the female member of a strut embodying myinvention and improvements. y

Figure 3 is an end view thereof from the left side of Fig. 2.

Figures fi and 5 are views corresponding to Figs. 2 and 3, of a blanksuitable for the production of said strut member by the practice of myimprovedprocess.

Figures 6 and 7 are corresponding views yand. all other showing saidblank after being subjected to the first swaging operation.

Figures 8 and 9 are corresponding views showing said blank after beingsubjected to the second swaging operation; and

FigureszlO and 1l are similar views showingthe blankfafter beingsubjected to the third swaging operation.

Referring now particularly to Fig. l of the drawing, in which I have,for purposes of clear and definite illust-ration, shown a strut of thegeneral type to which the present invention relates, as applied in Ausefor securing the cap or valve of the water nozzle of an automaticsprinkler in closed position, a designates the base portion of thesprinkler frame, al the arms thereof which connect said base portionwith the abutment 0,2, a"x the valve or cap which closes the waterdischarge nozzle of the sprinkler, a* a stressing screw having threadedengagement with a hole formed through the abutment a2, a5 and aarticulated male and female strut members inserted between the cap` orvvalve as and the inner end ofthe stressing screw a4, the remote ends ofsaid strut members being lrounded and engaging recessed seats or bearings formed in the valve cap a3 and in the end of the stressing screwo4, respectively,

vand a7 a fusible link which connects the ends of the lever arms formingparts of the' strut membersaf, a6. In the drawings, the strut membersa5, a6 are shownin full lines parts of the sprinkler indotted lines.

lAs regards its usual features and excepting as hereinafter particularlydescribed and pointed out, said sprinkler may be of anyusual or approvedconstruction, and will readily be understood by persons skilled intheart from an examination of the drawings, without a description thereofin detail.

In accordance with my improved process of manufacture, the strutvmembersa5, a, are formed from blanks punched from a plate of suitable ductilesheet metalpreferably phosphorbronze-substantially .128 of an inch inthickness.

In Figs. 4k and 5 of the drawings, I have shown a blank, designated as awhole as, adapted for making either the male strut member a5 or thefemale member a, said blank comprising a portion l adapted for formingthe strut portion proper of said strut member, and an. arm portion 2.

In accordance with my improved process, the blanks as are wrought to theform of the finished strut members 0,5, ai, by subjocting them to foursuccessive forgfng or swag'ing operations in dies which progressivelyconform to the shape of said strut members. As a result ofextendcd testsand experiments, I have discovered that said blank can be brought tofinal shape by four different swaging operations performed on said blankin succession, the first of said operations i mparting` to the blanksubstantially the shape shown in Figs. G and 7, the second swag'ingoperation imparting to said blank the shape shown in Figs. 8 and 9, thethird operation imparting to thc blank the shape shown in Figs. 10 and11, and the fourth and final forging operation conforming said blank tothe shape of the finishedstrut member,`as the female member shown inFigs. 2 and 3.

By means of my improved process of manufacture, I am able to producestrut members a5, a, in large quantities, all of which will be facsimiles of one another; which will be relatively many times strongerthan struts of the same general type produced by present methods ofmanufacture, and the cost of which .is rela tively very much less.

Struts made in accordance with my improved process possess a greatadvantage over struts madein any other manner of which I have anyknowledge, in the respect that, due to the forging and swaging` to whichthey are subjected in manufacture, they are much stronger than otherstruts, first, because they are rendered very tough by said forging andswaging operations, second, because said operations compact andconsolidate the surface ofthe metal, rendering it very dense andimpart-ing to it great strength and resistance to withstand the stresseswhich it will sustain in use, and third, because, due to the process ofmanufacture, the struts are iinished complete by theforging and swagingoperations to which they are subjected, Without a separate finishingoperation, thus materially reducing the cost of production of saidstruts.

Having ascertained by test and experiment the form of the blank mostdesirable for use in the manufacture of the strut members in accordancewith my improved process, the number of forging operations to beemployed and, in a general way the successive shapes to which the blanksare to be wrought,

skilled mechanics can readily produce con' forming vdies suitable forperforming the different steps of my improved process of manufacture andit will not, therefore, be

necessary to either show or describe said dies in detail.

I claim- 1. rlhe process of making struts for auto'- matic sprinklers,which consist in punching blanks substantially of the shape shoWn'inFigs. 4; and 5 from suitable sheet metal, subjecting the portion 1 ofsaid blank to a swaging operation in the directions indicated by thearrows, Fig. t, bringing it substantially to the form shown in Figs. 6and 7, subjecting the entire blank to a swaging operation in thedirections indicated by the arrows, Fi 6, bringing' it substantially tothe form shown in Figs. 8 and 9, subjecting the entire blank to aswaging operation in the directions indicated by the arrows, Fig. 9,'bringing it substantially to the form shown in Figs. 10 and 11, and inthen subjecting the entire blank toa swaging operation in the directionsindicated by the arrows, Fig. 10, bringing it substantially to its finalform shown in Fi's'. 2 and 3, each swaging operation beingsubstantiallyV at right angles to the last preceding operation wherebyfins or ribs formed on the blankin earlier swaging

